This invention relates to a back-up brake assembly, and particularly such an assembly used in a strip feeding mechanism for feeding partition strips to a partition fabricating machine. An example of the feeding mechanism referred to is disclosed in U.S. Pat. No. 3,304,082. The fabricating machine referred to may be generally of the type disclosed in U.S. Pat. No. 2,163,923.
Specifically, the back-up bake assembly of this invention is an improvement over the device best shown in FIGS. 8 and 11, and also shown in FIGS. 14, 17, 18, and 19 of U.S. Pat. No. 3,304,082, incorporated herein by reference. The reference numerals hereinafter referred to in this background section are those of said referenced patent.
The back-up brake assembly is identified by the reference numerals 105 through 121 and is mounted at the top of a vertically disposed elongated plate identified by the numeral 51. The function of the back-up brake assembly is to prevent back-up movement of the partition strip 50 upon reciprocation of the partition strip feeding assembly 37.
The partition strip feeding assembly feeds a partition strip 50 by a reciprocating movement into position for assembly with transverse partition strips. As the reciprocating feeder, as shown in FIGS. 29, 30, and 31 of said patent, retracts, it moves along the surface of the partition strip it has just fed with a tendency to pull that strip rearwards. The back-up brake assembly prevents such rearward movement of the strip.
Although the back-up brake assembly described in said patent operated satisfactorily, it had certain disadvantages. The primary disadvantage was that proper operation required that the edge 119 of the finger 118 engage the edge of one of the cutouts 215 in the partition strip 50. The purpose for the cutouts 215 is for reception of the cross partition strips. The prior art brake assembly would not brake or hold the strip unless the edge 119 engaged the edge of a cutout 215. For this reason, adjustability of the location of the brake assembly was required along the length of the hood 105 by means of the lead screw 111 so that the edge 119 could be accurately located relative to the cutouts 215. Thus, a time consuming adjustment was required whenever a change in strips with different cell sizes was made, and minor adjustment was often required during operation with partition strips of a single cell size since the adjustment was quite critical.
It was even necessary to have different sizes of hoods both in length and in height in order to accommodate the wide variations in cell size requirements. Because of the necessity for adjusting the location of the brake by means of the lead screw, and because the brake had to be located one cell size back from the assembly point, a single size hood assembly could not accommodate the total expanse of cell size variation. Also, because the cutouts were longer for deep cell sizes, brake assemblies with hoods of different heights had to be used. Thus, setup time was required to change from one size brake assembly to another where partition cell size changes so required. This had the further disadvantage of requiring an inventory of different sizes of brake assemblies.
The prior art device would not operate satisfactorily without engagement of the edge 119 with the edge of a cutout 215 because of the operation of the spring. The spring would have had to supply the holding force, and if it were made strong enough for this purpose, the strips could not pass forwardly between the finger 118 and the wall of the hood 105.
The improvement of this invention eliminates these disadvantages and provides a back-up brake assembly that firmly holds or brakes the partition strip against back-up movement without the need for adjustment as with the prior art device, and without the need to engage the edge of a cutout in the partition strip. Only one size brake assembly is needed and it can be made considerably smaller.